1. Field of the Invention
The present invention relates generally to an input apparatus and input method thereof and, more particularly, to an input apparatus and method using optical sensing, and to a portable terminal using the input apparatus and method.
2. Description of the Related Art
Along with recent advances in communication technology, a variety of portable terminals such as personal digital assistants (PDAs) and mobile phones have been developed and are in widespread use. From the viewpoint of user interfaces, particularly input apparatuses, various types of user interfaces including keypads having hardware buttons and soft keypads using touch screens have been applied to the portable terminals.
Such a conventional user interface normally includes mechanical elements attached to the base of a portable terminal. That is, desired signals are input through touching particular surfaces or elements.
FIG. 1 is a view illustrating a portable terminal having a conventional input apparatus. The portable terminal 100 of FIG. 1 is a slide-type phone comprising a main body 120 and a sub-body 110 slidable on the main body 120. Referring to FIG. 1, in the conventional portable terminal 100, a keypad 121 serving as a main input apparatus is installed in the main body 120. Thus, the main body 120 is configured to have a given thickness and volume to process input signals from the keypad 121.
The conventional user interface including a mechanical element such as a hardware keypad or touch pad at the base of a portable terminal significantly increases the thickness and size of a portable terminal, thus limiting miniaturization of the portable terminal.